SpudFiles

Sorry if this is a stupid question but why is it that everywhere I look, (Lowes and Home Depot) the only pvc size reducers are ABS. And that's to say I can even find the size I'm looking for. The first gun I made was the ugliest thing you could imagine. So now I want to do everything right this time. I know that I want a clear 4" chamber with propane injection, http://www.bcvids.com/store/product_inf ... ucts_id=59, and a chamber fan. I guess what I'm asking is where can I find adapters that go from 4" to Tennis or golf ball sizes.

I would be really, really surprised if they didn't have bushings. Just ask the one of the people there if they have any and if they don't, ummm well tell them they should get a life.

You need a flush bushing and coupler.

Get away from home owner junk stores and go to a real plumber's supply. I made friends at the supply , they have come up with very good ideas to help me out. If ya can learn the names of parts ,it helps.
Come right out and tell'em what your building. I drew a pic once and the guy walked around the shop and picker up all the parts. I had to explain
some stuff but the drawing helped loads. Research the parts and termanolgy, make a list.
they get a laugh when you don't tell 'em cause they know what your building. Make sure to go back and show off the finished product.
All the plumbers will tell their stories 'bout guns,were not the first to do this.

So something like this is a bad idea?

Sure is. CHances are(very high) they it is not pressure rated, though since its only a propane combustion you shouldn't need to worry though a Bushing would be ideal.

I dont think so because I saw a few guns with those kind of reducers. I may be wrong because I dont have experience in combustions except a Powerade bottle combustion. In a full size one, personally I would use all pressure fittings. You can get all kinds of fittings here http://www.mcmaster.com
and also here http://www.hardwareandtools.com/icat/pipingandtubing